According to Maakaari, the sale of real estate must be done in writing. The seller and the buyer or their representative must sign the deed of sale. The transaction confirmer must confirm the transaction in the presence of all the signatories of the transaction deed.
The sales verifiers and their contact information can be found on the National Land Survey's service pages at http://www.maanmittauslaitos.fi/kiinteistot/kiinteistot-ja-kiinteistokauppa/etsi-kaupanvahvistaja.
If you are looking for the owner of a property: Find out the owner of the property | Land Surveying Office
The city offers transaction confirmation services related to real estate transactions. Urban planning transaction confirmation: Sini Ojalainen.